2024 10m QRSS Challenge: - G0PKT, G0MBA & AE0V 15th Jan

As part of a challenge for 2024, I've decided to see how many QRSS signals I could capture on the 28 MHz band during the year.

QRSS are very slow morse code transmissions where the dots and dashes are several seconds long and the signals are decoded by looking at a waterfall display on a screen rather than listening to the signal.

The QRSS signals are usually just below the WSPR signals on the amateur radio bands. This means it's possible to have your PC decoding WSPR signals up around 1500 Hz while you look at the QRSS signals about 500 Hz or so lower in the audio spectrum at the same time.

2024 #3 & #4 - G0MBA & G0PKT... The QRSS signals shown above were captured at about 10:40 UTC and it shows the QRSS trace from G0MBA and G0PKT who are 650kms to the east of my location in Essex, England. From what I know, I think both are running 0.2-watts into vertical antennas.

You'll notice that the signals have a slight 'fuzz' as opposed to a clean tone. I hear/see these two stations practically every day and I think the signals are F2 layer backscatter. If I was to try again during the Sporadic-E season during the summer, both signals would be nice and clean.

At 650kms, both signals from G0MBA & G0PKT are way too far for ground wave and too close for normal F2. The signals are probably being propagated off the F2 layer, being reflected in some distant region and then returning to my location.

2024 #5 - AE0V...In the afternoon, I got a capture of the QRSS signal of AE0V in Minnesota (EN34FU) in the USA who is about 6,000kms from my location.

Ned, AE0V reports using a solar powered transmitter with no battery storage running 100mW into a 1/4 wave stainless whip about 8m above the ground.

The signal from the USA is easily explained as it's via multi-hop F2 layer propagation. 

In summary... That brings the QRSS tally so far for 2024 up to 5-callsigns & 3 DXCC.

1) 08 Jan 2024: VE1VDM - DXCC #1
2) 10 Jan 2024: VA1VM
3) 15th Jan 2024: G0MBA - DXCC #2

4) 15th Jan 2024: G0PKT

5) 15th Jan 2024: AE0V - DXCC #3

Backscatter on 28 MHz - 2nd Nov 2023

For well over 12-months, I have had my radio tuned to the WSPR frequency of 28.1246 MHz on the 10m band and I feed the decoded signals up to the WSPRnet website.

While I can see the WSPR signals clearly on the waterfall display, I can also see the very slow morse QRSS signals as well just a few hundred Hz below.

The image above shows the QRSS signals I could see on the 2nd of November 2023 and the locations of the stations are shown in the map at the start of the post.

The screenshot above shows a good capture of AE0V in the USA at about a distance of 6000kms. Ned, AE0V reports using a solar powered transmitter with no battery storage running 100mW into a 1/4 lamba stainless whip about 8m above the ground.

The signals from the USA and Canada are easily explained as they are via F2 layer propagation. The signals I find unusual are the ones from the England which are in the region of 500 to 650kms.

The trace from the 0.2-watt signals of G0PKT and G0MBA are there nearly all the time when the band is open. It's not F2 propagation in the usual sense as it's too close and it's not Sporadic-E.

I believe that it's backscatter just like what the military use for their over the horizon radar systems (OTHR). 

In this case, the 28 MHz band is open with F2 layer propagation and the signals from G0PKT & G0MBA are being reflected back towards my location from some distant point.

As an example of how consistent these signals are, I have decoded the WSPR signal of G0PKT about 1,000 times in the last 3-weeks. And that's a signal that's supposed to be in my 'skip zone' where it's supposed to be hard to reach.

There's nothing new about this, it's just that in this modern age of weak signal modes and waterfall displays, we can now see these very weak signals more clearly. 

If you're using FT8 on the higher HF bands and you see lots of reports from stations that about 200-600kms away then F2 backscatter is probably the reason.

QRSS signals heard on 28 MHz - 1st Nov 2022

Every day, I leave my HF radio on the 28.1246 MHz to listen for WSPR signals. My PC then decodes these and sends the reception reports up to WSPRNet website for others to see.

The QRSS (very slow morse code) band is just a few hundred Hz below the 10m WSPR band and I noticed in the WSPR waterfall that two QRSS signals were present so I had a look.

The image above shows the QRSS signals that I was hearing over a period of about 20-25 minutes on the 1st of November 2022.

VE1VDM in Canada and G0PKT in the east of England had reasonable signals and they were the two I had noticed initially. G6GN in England is also present but quite weak. There are other very weak QRSS signals as well but I was unable to ID these.

The locations of the relevant stations are shown on the map below.

VE1VDM in Nova Scotia is 4000kms from my location and is easily explained as it's an ideal one F2 layer hop away on 28 MHz.

The signals from G6GN at 400kms and G0PKT at 650 kms are not so easily explained. If it was the Summer months then we might think it was Sporadic-E but, this was the first of November AND G0PKT is pretty much there all of the time every day when the band is open.

I suspect that I am receiving these signals via F2 layer backscatter. In the past (pre digital days), backscatter signals were pretty much buried in the noise with the SSB and CW modes. Now however, WSPR has no problem decoding signals that are 20dB below the noise level and I can see QRSS signals which are in the region of -15 to -20dB.

I think a lot of those 'close in' signals that we are now seeing on WSPR or FT8 on 28 MHz are in reality via backscatter.

You can see from the map above all of the WSPR stations I heard on 28 MHz on the 1st of November. Meteor Scatter? Forward scatter via Sporadic-E? I'm opting for F2 layer backscatter.

I'm using an omni-directional vertical on 28 MHz so I can't beam headings. Maybe someone else wants to do some tests? See which direction those 'close in' signals are strongest. The direct path OR beaming in some other direction at a potential back-scatter point?

28 MHz Report for Sun 9th May 2021

Sunday 9th May 2021: While the 9th didn't seem to be as good as the 7th & 8th, there were still lots of Sporadic-E signals on 28 MHz for most of the day. Again, I spent most of the day on WSPR with the receive map for me shown above.

This time, I heard 7 stations running 50mW or less.

(y-m-d) TX txGrid RX rxGrid MHz W SNR drift km
2021-05-09 10:56 G4KPX JO02dj EI7GL IO51tu 28.126063 0.005 -6 
2021-05-09 09:06 DJ4RH JN49bx EI7GL IO51tu 28.126088 0.01 -23 
2021-05-09 10:06 PD0KT JO33le EI7GL IO51tu 28.126094 0.01 -23 
2021-05-09 09:56 OZ0RF JO65fr EI7GL IO51tu 28.125994 0.02 -23 
2021-05-09 08:36 DL1WER JN58cd EI7GL IO51tu 28.126116 0.05 -18 
2021-05-09 08:54 DK9ES JO31 EI7GL IO51tu 28.12608 0.05 -24 
2021-05-09 18:04 ON4LUK JO11  EI7GL IO51tu 28.126197 0.05 -23 

When the skip went short, I managed to get two QRSS (very slow morse) plots from two stations east of London, about 600kms from me.

I also spent some time monitoring the FT8 frequency and I heard 279 stations in 36 countries.

QRSS Signals from the UK on 28 MHz - Tues 19th May 2020

QRSS is a mode where a morse code signal is sent very slowly so that it can seen on a screen rather than heard by ear. This allows signals that can be up 20dB below the noise level to be seen.

While it might seem outdated by some of the more modern digital modes like WSPR or FT8, what is really interesting about QRSS is that you can visually see the propagation moving around.

On Tuesday the 19th of May 2020, there was really intense Sporadic-E on 28 MHz with a very short skip opening from Ireland to the UK. This allowed me to hear the QRSS signals from stations near London as shown on the map below....

The key points here before we look at the QRSS plots are...

a) G6NHU, G0MBA & G0PKT are all very close to each other and about 650 kms from my location.

b) G0FTD is about as far but is 50 kms to the south of the cluster of three.

c) M0GBZ is along the same path as the group of three but is about 90 kms closer at 560 kms.

d) The shorter the distance then the smaller the Sporadic-E footprint tends to get.

As shown above, it tends to be long and narrow and this will be shown in the QRSS examples below.

***

Screen grab 1.....

In this image above, you can see all of the signals. G0FTD has two transmitters and is the weakest.

***

Screen grab 2...

In this image, the Sporadic-E footprint moves north and even though G0FTD is just 50 kms from the more northern stations, he moves outside the footprint.

The cluster of three remain remain the same while M0GBZ disappears as the skip lengthens for a while before coming back.

* * *

Screen grab 3...

In this plot, the Sporadic-E skip distance increases and M0GBZ disappears. G0FTD disappears for about two minutes before the footprint moves south again.

On the right hand side, all of the QRSS signals are there but they now become quite fuzzy which may indicate multipath. Perhaps the Sporadic-E has broken up into several clouds rather than maybe the single one before.

In conclusion..... This was the my first reception this year of the UK QRSS stations on 28 MHz and as you can see from what's written above, the plots show a lot.

From what I now, the QRSS mode is the only one where you can actually see on a screen how the propagation is moving around in real time.

Listen on 28.0008 MHz on CW for these stations running just a few hundred milliwatts.